The update comes with a refresh of Samsung's TouchWiz UI. SamMobile notes that many of the changes will be in performance, rather than appearance, but users should see sharper colours, changes to the default Samsung keyboard and some UI tweaks.

We've checked the Galaxy S4 units in the office, and we've had no update at this time. However, the update is being rolled out in phases, and carrier-branded phones may take longer, as the telcos often have to approve the update before allowing it over the network.